Carboxymethylated derivatives of diand tri-saccharide compounds and detergent compositions containing them

ABSTRACT

CARBOXYMETHYLATED DERIVATIVES OF DISACCHARIDE COMPOUNDS SUCH AS SURCROSE AND LACTOSE AND TRISACCHARIDE COMPOUND SUCH AS RAFFINOSE ARE PROVIDED. THSES COMPOUNDS ARE USEFUL AS SEQUESTERING AGENTS, E.G., WATER SOFTENERS, AND ALSO AS DETERGENCY BUILDERS IN DETERGENT COMPOSITIONS. BUILT DETERGENT COMPOSITIONS ARE ALSO PROVIDED.

United States Patent Office CARBOXYMETHYLATED DERIVATIVES F DI- ANDTRI-SACCHARIDE COMPOUNDS AND DETERGENT COMPOSITIONS CONTAINING Int. Cl.Clld 3/22 US. Cl. 25289 4 Claims ABSTRACT OF THE DISCLOSURECarboxymethylated derivatives of disaccharide compounds such as sucroseand lactose and trisaccharide compounds such as raflinose are provided.These compounds are useful as sequestering agents, e.g., watersofteners, and also as detergency builders in detergent compositions.Built detergent compositions are also provided.

This is a division of application Ser. No. 811,605, filed Mar. 28, 1969now Pat. No. 3,634,392.

This invention relates to carboxymethylated diand trisaccharides whichare useful as sequestering agents and also as detergency builders fororganic water-soluble synthetic detergents.

The compounds of the present invention have a formula selected from thegroup consisting of:

0-9; A 6 J) i t 1: i i 7 Formula A Formula B 3,686,124 Patented Aug. 22,1972 in which each Y represents H or CH COOH, at least one Y being CHCOOH.

Compounds depicted by Formula A are derivatives of sucrose, (3 11 011,molecular weight, 342.2. Sucrose is a disaccharide ha ing monocliniccrystalline form. It hydrolyzes to fructose and glucose. It is widelyfound free in juice of all land plants, in particular sugarcane, sugarbeet, and sugar maple.

Compounds depicted by Formula B are derivatives of lactose, C H O .H O,molecular weight, 360.2. Lactose is a disaccharide found free in milk ofall mammals and also in pollen from Forsythia. It hydrolyzes to glucoseand galactose.

Compounds depicted by Formula C are derivatives of raffinose, C H O 5HO, molecular weight, 594.4. Ratlinose is a trisaccharide derived fromsugar beets, cottonseed, eucalyptus, and other plants. It hydrolyzes totruetose, glucose, and galactose. It has colorless monoclinic needles,d.-1.465, M. PT. 119.

Further description of the parent materials is found in volume 13,Encyclopedia of Chemical Technology, Kirk and Othmer, Copyright 1954 bythe Interscience Encyclopedia, Inc.

In the preceding formulae, as noted, each Y represents hydrogen or acarboxymethyl group. Such car-boxymethylated compounds have beendiscovered to possess useful sequestering properties and detergencybuilder properties. Both of these properties are improved with anincrease in the number of carboxymethyl groups present in each compound.The maximum degree of substitution, D.S. (num ber of carboxymethylgroups) for sucrose and lactose is 8 and for rafiinose is 11. Inpracticing this invention in a sequestering application, it is preferredto use compounds having a degree of substitution greater than 3. Foroptimum detergency builder properties, a degree of substitution ofgreater than 50% in each instance is preferred,

e.g., greater than 4 in the case of sucrose and lactose and greater thanabout 6 in the case of rafiinose.

The carboxymethylated derivatives of sucrose, lactose,

- I and rafiinose provided by the present invention can be i prepared bymany carboxymethylating procedures. A typical preparative method, andone which is exemplified hereinafter, comprises a reaction betweensucrose, lactose, or raifinose with an alkaline material such as sodiumhydroxide to form an alkoxide of the polyhydric alcohol. The reactionproduct of this reaction is then reacted with a compound such as sodiumchloroacetate and the mixture is allowed to digest. An ordinary work-upfollows these reactions in order to recover the desiredcarboxymethylated sucrose, carboxymethylated lactose, orcarboxymethylated rafiinose, depending on whatever the starting materialwas.

3 I s The following examples are given by way of specific illustrationfor preparing the compounds of thisinvention r 7 EXAMPLE I Preparationof carboxymethylated sucrose A solution of 4.3 g. (0.10 equivalent) ofsucrose in 19.6 ml. of water was mixed with 7.2 g. (0.18 mole) of groundsodium hydroxide and this mixture was blended for ten minutes. To thiswas added 21.4 g. (0.18 mole) of sodium chloroacetate and blending wasagain carried out for ten minutes. The mixture was then allowed to standand digest with occasional blending, for three days until all of thesodium chloroacetate had reacted. This procedure of adding sodiumhydroxide and sodium chloroacetate in equivalent amounts, followed by adigestion step, was reported six times to arrive at a completedreaction. Water was added, as needed, to maintain a pasty consistency.

After completion of the reaction, the reaction mixture was dissolved inwater and the product was then precipitated by the addition of excess ofmethanol. The precipitate was collected by filtration, redissolved inwater, and then the precipitation-isolation procedure was repeated.There was obtained 5.4 g. of product. Final purification was effected bygel filtration using Sephaclex G-IO resin.

The product was analyzed by dissolving a weighed amount of it in water,passing this solution over a column of a strongly acidic ion exchangeresin, and then titrating the resulting eluant with standardized sodiumhydroxide solution. Analysis indicated an equivalent weight of 120 forthe carboxymethylated sucrose product which corresponds to a degree ofsubstitution of 8.

EXAMPLE II Preparation of carboxymethylated lactose A solution of 4.3 g.(0.10) equivalent of lactose in 19.6 ml. of water was mixed with 7.2 g.(0.18 mole) of ground sodium hydroxide and this mixture was blended forten minutes. To this was added 21.4 g. (0.18 mole) of sodiumchloroacetate and blending was again carried out for ten minutes. Therest of the procedure of Example I was followed and the productrecovered was carboxymethylated lactose having a degree of substitutionof 8. Carboxymethylated lactose with degrees of substitution of 6, 5, 4,2, or 1 are prepared by decreasing the amount of sodium hydroxide andsodium chloroacetate added to the reaction and also by using shorterdigestion times.

EXAMPLE III 7 Preparation of carboxymethylated rafiinose Following theprocedure described in Example I, 5.4 g. of raffinose pentahydrate (0.1equivalent of ratfinose) and 31.9 ml. of water were reacted. Sodiumchloroacetate was added as noted in Example I followed by digestion forabout three days.

The compounds of this invention possess a useful sequestering propertywhich makes them valuable for treating aqueous solutionscontaining"polyvalent'metal 'ion's (iron, calcium, magnesium, and thelike) by adding to a solution an effective amount of one of thecompounds described herein, or a mixture of such compounds. Ordinarilythe amount employed ranges from .25 part per million to 10,000 parts permillion of the aqueous solution. This embodiment of the presentinvention is based on the discovery of the sequestering properties ofthe carboxymethylated compounds described herein. The optimum amount forany given water treatment application can be readily determined bymerely adding a sufiicient amount of sequestrant to accomplish thedesired objective. The useful sequestering properties of the compoundsof the present invention are demonstrated by a swatch-dip procedurewhich measures the relative sequestering ability of a compound. Theprocedure involves the use' of a fabric swatch impregnated with soap andan aqueous solution containing, a predetermined level of calciumhardness minerals. Briefly, the procedure first calls for preparing anaqueous solution containing the hardness minerals, at a pH of 10, andthen dipping into it or immersing in it a fabric swatch which has beenimpregnated with a measured amount of soap. The swatch is allowed toremain in the solution for a predetermined amount of time. During thisimmersed period, free calcium in the solution is being absorbed by'thefabric swatch. The amount of free calcium absorbed is then measured. Theidentical procedure is then repeated but with a predeterminedconcentration of a sequestrant compound added to the aqueous solutioncontaining the calcium ions. The amount of calcium absorbed in thissecond instance is also measured. Comparisons are then made between thetwo results, i.e., those obtained without the use of a sequestrantagainst those results obtained with the use of a sequestrant.Differences between the amounts of calcium absorbed in demonstrationswith and without sequestrants is attributed to the capability of theseques trant to sequester or complex the calcium ions and, thereby,reduce the amount of free calcium ion available for absorption upon theimmersed fabric swatch. A percentage is calculated which is calledpercent hardness retained by sequestrant.

Several demonstrations were conductedin this manner and comparisons weredrawn between the performance of compounds of the present invention andsodium tripolyphosphate (STP), sodium citrate, and sodium pyrophosphate.These latter compounds are three known sequestering agents. The dataobtained from these demonstrations are tabulated below in Table I andindicate the usefulsequestering properties of representative compoundsof the present invention, i.e., carboxymethylated sucrose of Example I,carboxymethylated lactose of Example II, and carboxymethylated raffiuoseof Example III.

1 Concentration of sequestrant in solution.

The same work-up procedure was practiced to recover the desiredcarboxymethylated raflinose. The recovered product was analyzed for anequivalent weight of 130 which corresponds to a degree of substitutionof about 10.8 out of a maximum of 11. Routine adjustments in bothreaction time and digestion time result in the preparation ofcarboxymethylated rafiinose having lesser degrees of substitution.

In addition to the useful sequestering properties which thecarboxymethylated derivatives of sucrose, lactose, and rafiinose of thisinvention possess, they are also useful as detergency builders. Inpracticing this builder embodiment, the carboxymethylated buildercompounds described and illustrated above are used in conjunction withorganic synthetic detergents to provide built laundering and detergentcompositions.

The organic water-soluble synthetic detergents useful in the presentinvention include the anionic, nonionic, zwitterionic, and ampholyticdetergents which are illustrated and exemplified in detail in U.S. Pat.3,159,581 issued on Dec. 1, 1964, to Francis L. Diehl and assigned tothe Procter & Gamble Company. The patent is hereby incorporated hereinby reference and especially the disclosure beginning at column 3, line74, and extending to column 5, line 59. There are numerous otherdetergents which fall within the named classes of detergents and theycan also be usefully employed herein. Olefin sulfonate detergents suchas those described in US. Pat. 3,332,880 (also incorporated herein byreference) are especially useful in combination with the buildercompounds of this invention.

In practicing the present invention, a detergent and launderingcomposition comprises an organic water-soluble synthetic detergent and acarboxymethylated surcose, lactose, or rafiinose builder in a proportionby weight, respectively, of :1 to 1:10 and preferably 2:1 to 1:5. Thebuilt composition can be formulated as a liquid or solid form. Builtliquid compositions having an aqeous or alcoholic (ethanol) base areespecially useful. Solid formulations such as tablets, granules,powders, flakes, and the like find Widespread application.

In a detergent formulation of this invention, minor amounts of othermaterials can be present which make the product more effective or moreaesthetically attractive. The following are mentioned by way of example.A soluble sodium carboxymethylcellulose or starch can be added in monoramounts (.2-2%) to inhibit soil redeposition. A tarnish inhibitor suchas benzotriazole or ethylenethiourea may also be added in amounts up toabout 2%.

Fluorescers, perfume, and color While not essential in the compositionsof the invention, can also be added in amounts up to about 3%. Analkaline material such as sodium hydroxide or potassium hydroxide can beadded in minor amounts as supplementary pH adjusters. Other suitableadditives include water, brightening agents, enzymes, sodium sulfate,and sodium carbonate, buffers, fillers and the like.

In addition, corrosion inhibitors can also be present. Soluble silicatesare highly effective inhibitors and can be added to certain formulas ofthis invention at levels of from about 3% to about 8%. Alkali metal,preferably potassium or sodium silicates having a weight ratio of SiO MO of from 1.0:1 to 2.8:1 can be used. M in this ratio refers to sodiumand potassium. A sodium silicate having a ratio of SiO :Na O of about1.611 to 2.45:1 is especially preferred for economy and effectiveness.

In the embodiment of this invention which provides for a built liquiddetergent, a hydrotrope can at times be found desirable. Suitablehydrotropes are water-soluble alkali metal salts of toluenesulfonate,benzenesulfonate, and xylenesulfonate. The preferred hydrotropes arepotassium or sodium toluenesulfonates. The hydrotrope salt may be added,if desired, at levels from 0% to about 12%. While a hydrotrope is notordinarily found necessary, it can be added if so desired for any reasonsuch as to produce a product which retains its homogeneity at a lowtemperature.

The built detergent and laundering compositions of this inventionprovide best cleaning results when used in aqueous solutions having a pHof 9 to 12, preferably 9.5 to 11.5. This point can be taken into accountin formulating the complete built composition by including alkalineingredients to satisfy the pH requirement. Alternatively, alkalinematerials can be added directly to the washing solution to bring the pHinto the 9-12 range.

The compositions of this invention provide best cleaning results whenused at a suflicient level to provide in solution a concentration ofbuilder in the range of .02% to .5 by weight, and preferably .03% to.3%.

The following built detergent compositions illustrate this embodiment ofthe present invention:

EXAMPLE IV A granular built detergent composition having the followingcomposition provides effective laundering results in aqueous solutionshaving a pH of about 9:

20% sodium dodecylbenzene sulfonate, dodecyl being a linearstraight-chain radical 50% sodium carboxymethylated sucrose builder(D.S.==

8) of Example I 14% sodium sulfate 6% sodium silicate 10% water In thisexample, the sucrose builder can be replaced by a sodiumcarboxymethylated lactose of Example II (D.S.=8) or sodiumcarboxymethylated raflinose (D.S.= 11) without any loss in cleaningproperties.

EXAMPLE V An effective granular built detergent composition comprises:

17.5% sodium olefin sulfonate (having 12-16 carbon atoms) 20.0% sodiumtripolyphosphate 20.0% sodium pyrophosphate 10.0% sodiumcarboxymethylated sucrose (D.S.=7)

16.0% sodium sulfate 10.0% sodium silicate 4.0% water In this example,the sodium pyrophosphate can be replaced on an equal weight basis bysodium carboxymethylated lactose (D.S.=5), sodium carboxymethylated(D.S.=3), sodium carboxymethylated sucrose (D.S.=6), sodiumcarboxymethylated rafiinose (D.S.=8), or sodium carboxymethylatedraffinose (D.S.=4).

In addition, the sodium olefin sulfonate detergent can be replaced bysodium tallow alkyl sulfate or sodium coconut alkyl sulfate.

EXAMPLE VI An excellent built liquid detergent composition according tothis invention comprises:

6% sodium dodecylbenzene sulfonate (the dodecyl radical beingpolypropylene predominantly tetrapropylene averaging 12 carbons).

6% dimethyldodecylamine oxide 20% sodium carboxymethylated lactose(D.S.=6)

8% potassium toluenesulfonate 3.8% sodium silicate (ration SiO :No O of2.45:1)

0.8% carboxymethyl hydroxyethyl cellulose Balance water In practicingthe built detergent composition embodiment of the present invention, thecarboxymethylated sucrose, lactose, and raffinose builders describedherein can be used separately or in combination either with each other,or in combination with any inorganic alkaline detergency builders ororganic alkaline sequestering builders such as sodium nitrilotriacetate,sodium ethylenediaminetetraacetate, sodiumethane-l-hydroxy-l,l-diphosphonic acid, sodium polyitaconate, or sodiumpolymaleate.

As detergency builders, the carboxymethylated sucrose, lactose, andraffinose are in a class with such builders as citrate and pyrophosphatesalts. This can be demonstrated by the following evaluation:

White dress shirts, cotton T-shirts and other fabrics are distributedamong various individuals. Each dress shirt and T-shirt is worn for onenormal working day under uniform conditions and the other articles areused for their generally intended purposes. The soiled items are thenwashed in an automatic agitating type washer, for a period of tenminutes, with detergent solutions at F. temperature, a pH of 10, and ahardness of 7 grains per gallon. After washing, the clothes are rinsedand then dried. (No fiuorescers or bleaches were used.)

Direct comparisons are made by a panel of five graders between pairs ofshirts and fabrics worn and soiled by the same individual. The dressshirts, T-shirts and other fabrics used are graded on the degree ofwhiteness and the degree of cleaning obtained, paying particularattention on this latter feature to the dress shirt collars and cuffs.The term cleaning or cleanliness denotes the ability of a washingcomposition to remove actual soil lines or deposits such as the creaselines of collars and cuffs where the soil is deeply embedded. Whiteness,on the other hand, denotes a more general concept which measures theability of a cleaning composition to whiten areas which are onlyslightly or moderately soiled. Clean washcloth size swatches of cottonterry cloth and muslin are washed along with the soiled clothes toarrive at an independent evaluation of the whiteness maintenance orwhiteness compositions. The relative cleaning elfectiveness of eachdetergent composition in each area is graded on a raw score under UV.-free artificial light, averaged, and then translated onto a -10 scalewherein the highest grade of is assigned to the relatively bestperformance obtained.

A sample detergent composition employed during the tests contains sodiumtallow alkyl sulfate as the detergent active, (the alkyl chain lengthdistribution of tallow alkyl sulfate was approximately 66% C18, 30% Cand 4% others), 50% of a builder such as sodium citrate, sodiumpyrophosphate, or the carboxymethylated sucrose, lactose, or ralfinosebuilders described herein, 6% sodium silicate and 24% sodium sulfate.The pH of the washing solution is 10.

By practicing this demonstration, it is seen that the builders of thisinvention are substantially equal in builder properties andeffectiveness in areas of cleaning and whiteness to sodium citrate andalkali metal salts of pyrophosphoric acid, e.g., sodium pyrophosphate.

The foregoing description of the invention has been presented describingcertain operable and preferred embodiments. It is not intended that theinvention should be so limited since variations and modificationsthereof will be obvious to those skilled in the art, all of which arewithin the spirit and scope of this invention.

What is claimed is:

1. A detergent composition comprising an organic synthetic detergentselected from the group consisting of anionic, nonionic, zwitterionic orampholytic detergents or mixture of these detregents and a detergencybuilder selected from the group consisting of carboxymethylated sucrose,carboxmethylated lactose, or carboxymethylated raffinose, the proportionby weight of detergent to builder being from 5:1 to 1:10.

2. A detergent composition according to claim 1 in which the builder isa carboxymethylated sucrose having a degree of substitution greater thanfour.

3. A detergent composition according to claim 1 in which the builder isa carboxymethylated lactose having a degree of substitution greater thanfour.

4. A detergent composition according to claim 1 in which the builder isa carboxymethylated raffinose having a degree of substitution greaterthan five.

References Cited UNITED STATES PATENTS 2,893,990 7/1959 Hass et al.25289 2,970,962 2/1961 Hass et a1. 252- 3,159,581 12/1964 Diehl 252526LEON D. ROSDOL, Primary Examiner W. E. SCHULZ, Assistant Examiner US.Cl. X.R. 252526

